5G: Adaptable Networks Enabled by Versatile Radio Access Technologies

• Published in: IEEE Communications surveys and tutorials 2017-01, Vol.19 (2), p.688-720
• Main Authors: Sexton, Conor, Kaminski, Nicholas J., Marquez-Barja, Johann M., Marchetti, Nicola, DaSilva, Luiz A.
• Format: Article
• Language: English
• Subjects: 5G mobile communication; Adaptability; cloud-RAN; cognitive networks; Communications equipment; Complement; Coupling; Flexibility; full duplex; massive-MIMO; Mobile computing; Modulation; new waveforms; Operation support systems; Radio; Radio access networks; Reconfiguration; Software; software defined networks; Software-defined networking; Virtual networks; Virtualization
• ISSN: 1553-877X; 1553-877X; 2373-745X
• DOI: 10.1109/COMST.2017.2652495

The requirements and key areas for 5G are gradually becoming more apparent, and it is becoming clear that 5G will need to be able to deal with increased levels of diversity in both the requirements it must fulfil and the technologies that it uses to fulfil them. The diverse and demanding requirements for 5G necessitate a shift away from the rigid networks of previous generations, toward a more versatile and adaptable network. Essential to enabling this level of adaptability in 5G networks will be the new radio access technologies that are employed. In previous generations, the radio access network (RAN) was composed of technologies and techniques that were tailored to satisfy the killer application of that era. In contrast, 5G will require versatile solutions that can be adapted to satisfy many different services and applications. The core network will also undergo fundamental changes, with increased levels of abstraction allowing for further reconfiguration of the network. The relationship between the RAN and core network will have a key role to play in managing and enabling adaptable networks. In this paper, we survey the choices and adaptability afforded by some of the radio access technologies being considered for 5G and explore how several system-level techniques, such as software-defined networking and cloud-RAN, can be utilized to enable and manage versatile 5G networks. Specifically, we focus on the relationship between new radio access technologies and emerging system-level techniques, examining how they may assist and complement each other. In this regard, we examine some tools such as virtualization and cognitive networks that can bridge this relationship. This paper is not intended to be a general survey on 5G, but rather a survey on how the requirements of flexibility and adaptability may be achieved in 5G through the coupling of versatile radio access technologies and emerging system-level techniques.